Carbon activation method and energy storage device thereof

ABSTRACT

A method of making activated carbon including:
         compressing a mixture of an alkali metal hydroxide, a carbon source, and a solid thermosetting polymer precursor into a pellet; and   a first heating of the compressed mixture, as defined herein; and   optionally crushing, washing, or both, the resulting first heated mixture, as defined herein; and   optionally a second heating, as defined herein.

CROSS-REFERENCE TO RELATED CO-PENDING APPLICATIONS

The present application is related to commonly owned and assigned U.S.application Serial Nos. USSN Application Ser. No. 61/894,990 filed onOct. 24, 2013, and U.S. Application Ser. No. 61/858,902 filed on Jul.26, 2013, entitled CARBON FOR HIGH VOLTAGE EDLCS” now U.S. Pat. No.______ (not available; notice of allowance), which mentions: a method offorming activated carbon, comprising: carbonizing a carbon precursor byheating the carbon precursor at a carbonization temperature effective toform a carbon material; and activating the carbon material by heatingthe carbon material at an activation temperature while exposing thecarbon material to carbon dioxide, wherein the carbon precursorcomprises phenolic Novolac resin, but does not claim priority thereto.

The entire disclosure of each publication or patent document mentionedherein is incorporated by reference.

BACKGROUND

The disclosure generally relates to the field of energy storage devices.

SUMMARY

In embodiments, the disclosure provides a method of making activatedcarbon, which method provides improved efficiency and cost benefits.

BRIEF DESCRIPTION OF THE DRAWINGS

In embodiments of the disclosure:

FIG. 1 shows an exemplary flow diagram summary for the disclosed methodof making activated carbon.

FIG. 2 shows an exemplary pore size distribution of the activated carbonof the present methods.

FIG. 3 shows exemplary chemical structure representations for a phenolformaldehyde based compound such as a phenolic Novolac resin.

FIG. 4 shows a graph of filter resistance versus particle size.

DETAILED DESCRIPTION

Various embodiments of the disclosure will be described in detail withreference to drawings, if any. Reference to various embodiments does notlimit the scope of the invention, which is limited only by the scope ofthe claims attached hereto. Additionally, any examples set forth in thisspecification are not limiting and merely set forth some of the manypossible embodiments of the claimed invention.

In embodiments, the disclosed method of making and using provide one ormore advantageous features or aspects, including for example asdiscussed below. Features or aspects recited in any of the claims aregenerally applicable to all facets of the invention. Any recited singleor multiple feature or aspect in any one claim can be combined orpermuted with any other recited feature or aspect in any other claim orclaims.

DEFINITIONS

“Include,” “includes,” or like terms means encompassing but not limitedto, that is, inclusive and not exclusive.

“About” modifying, for example, the quantity of an ingredient in acomposition, concentrations, volumes, process temperature, process time,yields, flow rates, pressures, viscosities, and like values, and rangesthereof, or a dimension of a component, and like values, and rangesthereof, employed in describing the embodiments of the disclosure,refers to variation in the numerical quantity that can occur, forexample: through typical measuring and handling procedures used forpreparing materials, compositions, composites, concentrates, componentparts, articles of manufacture, or use formulations; through inadvertenterror in these procedures; through differences in the manufacture,source, or purity of starting materials or ingredients used to carry outthe methods; and like considerations. The term “about” also encompassesamounts that differ due to aging of a composition or formulation with aparticular initial concentration or mixture, and amounts that differ dueto mixing or processing a composition or formulation with a particularinitial concentration or mixture.

“Optional” or “optionally” means that the subsequently described eventor circumstance can or cannot occur, and that the description includesinstances where the event or circumstance occurs and instances where itdoes not.

The indefinite article “a” or “an” and its corresponding definitearticle “the” as used herein means at least one, or one or more, unlessspecified otherwise.

Abbreviations, which are well known to one of ordinary skill in the art,may be used (e.g., “h” or “hrs” for hour or hours, “g” or “gm” forgram(s), “mL” for milliliters, and “rt” for room temperature, “nm” fornanometers, and like abbreviations).

Specific and preferred values disclosed for components, ingredients,additives, dimensions, conditions, times, and like aspects, and rangesthereof, are for illustration only; they do not exclude other definedvalues or other values within defined ranges. The articles and methodsof the disclosure can include any value or any combination of thevalues, specific values, more specific values, and preferred valuesdescribed herein, including explicit or implicit intermediate values andranges.

Electrical energy storage is needed in many applications, such aselectric/hybrid vehicles, portable electronic devices, power systems,etc. Batteries of various kinds have been used for most applications. Inrecent years, electrochemical double layer capacitors (EDLCs, a.k.a.ultracapacitors or supercapacitors) have emerged as an alternative tobatteries in applications that require high power, long shelf life, andlong cycle life. Energy storage in an EDLC is achieved by separating andstoring electrical charges in the electrochemical double layer at theinterface between a solid surface and an electrolyte. Activated carbon(or active carbon) is the most widely used material in EDLCs because thecarbon has a very large surface area, good electrical and ionicconductivity, excellent chemical stability, and low cost.

Typically activated carbon can be prepared by carbonizing a carbonaceousprecursor in an inert atmosphere (e.g., N₂ or Ar), at a high temperature(commonly hundreds of degrees Celsius), followed by physical (e.g.,using CO₂ or steam) or chemical (e.g., using KOH, K₂CO₃, NaOH, Na₂CO₃,AlCl₃, ZnCl₂, MgCl₂, or H₃PO₄, etc.) activation. Precursors includenatural materials (such as coal, nut shells, wood, biomass, etc.) andsynthetic materials (mostly polymers such as phenolic resin, poly(vinylalcohol) (PVA), polyacrylonitrile (PAN), etc.). Activated carbonsderived from non-lignocellulosic sources, such as wheat flour, cornmeal,corn starch, etc., have been described (see commonly owned and assignedU.S. Pat. Nos. 8,318,356 and 8,784,764). For EDLC applications, achemical activation process yields a carbon product having superiorperformance compared to a physical activation process. The mostsignificant of the chemical activation processes involves alkaliactivation, i.e., reaction of either KOH or NaOH with the carbon becausethis process yields carbon with the highest electrical performanceproperties. However, this process poses some significant safety andequipment issues which limit the utility. The activation takes place inat from 700 to 900° C., and since KOH melts at about 400° C., asignificant amount of potassium metal vapor is generated, which has twoconsequences. First, the furnace can easily corrode reducing the furnacelife and may cause a safety hazards that needs to be addressed viaexpensive safety measures. A silicon carbide lined furnace may be usedto reduce corrosion issue. However the cost of the furnace is thensignificantly higher. Second, the reaction of alkali and carbontypically generates foam during activation due to the release of severalgasses. At activation temperatures, the gases released can include, forexample, CO, CO₂, H₂O, and H₂. These gases can cause severe foaming ofthe batch mixture. The extent of foaming limits the use of the space inthe reactor vessel, such as to from about 10 to 30 vol %. So that only aminor amount of the reactor vessel, e.g., about 20 vol %, can be filledwith the feed reactants, which can severely limit the output of thebatch reactor and can increase processing costs and product costs.

Commonly owned and assigned WO2015/017200 (PCT/US2014/047728), mentionsa method to address the foam issue. Fats, oils, fatty acids, or fattyacid esters are used as an additive in the alkali, carbon reactionmixture to minimize foaming. When these additives react with the alkalithey can produce alcohol and/or water by-products. These by-products canbe undesirable because they can lead to increased potassium metal vaporgeneration.

Another known preparative activation method (commonly owned and assignedWO2011/110543; U.S. Pat. No. 8,927,103, to Kirschbaum) involves: mixingan inert (i.e. non-reactive) hydrophilic polymer (e.g., polyether);forming a pellet of the carbon, the KOH, and the polymer; and heatingthe pellet in an inert environment to activate the carbon. The methodreduces K volatilization due to reduced geometric surface area of thepellet or briquette compared to free powder, which briquetting reducesthe corrosion issue by internal containment, and leads to lower costs.The method is applicable only to a very fine particle sizes, forexample, 5 microns or less, and does not work with large particle sizecarbon (e.g., 100 micron) needed for an industrially viable process.

In embodiments, the disclosure provides a method of making activatedcarbon comprising:

compressing a mixture comprising an alkali metal hydroxide, a carbonsource, and a solid thermosetting polymer precursor into a pellet; and

a first heating of the compressed mixture at from 600 to 1,000° C., forfrom 10 minutes to 24 hours, for example, 850° C. for 2 hrs.

The “solid” aspect of the thermosetting polymer precursor refers to thephase state of the precursor at ambient temperatures.

In embodiments, the method can further comprise washing the resultingcompressed first heated mixture.

In embodiments, the method can further comprise a second heating of theresulting compressed, first heated, and washed mixture, at from 600 to1000° C., for from 10 minutes to 24 hours, for example, 650 to 700° C.such 675° C., for from 2 to 10 hrs, such as 5 hrs.

In embodiments, the method can further comprise placing the compressedpellet into a closed container having a vent, e.g., a galvanized paintcan having a press-fit seal and having a lid having a 5 mm diameterhole) prior to the first heating.

In embodiments, the method can further comprise crushing the resultingcompressed and heated activated carbon product prior to the washing.

In embodiments, the first heating can be accomplished, for example, in acontainer that is open to an external atmosphere, such as a crucible ina furnace having ambient air or an inert atmosphere.

In embodiments, the alkali metal hydroxide can be, for example, powderedKOH, powdered NaOH, and like powdered alkali metal hydroxides, thecarbon source can be, for example, powdered green coke, and thethermosetting polymer precursor can be, for example, a mixture of aphenolic resin and a cross-linking agent.

In embodiments, the alkali metal hydroxide and the carbon source can be,for example, in a weight ratio of from 1:1 to 4:1, such as 2:1,including intermediate values and ranges.

In embodiments, the thermosetting polymer precursor to the mixture ofthe KOH and the powdered green coke can be, for example, in a weightratio of from 1:2 to 1:20, such as 1:10, including intermediate valuesand ranges.

In embodiments, the second heating can be accomplished, for example, ina forming gas, in an inert gas, or in a combination thereof.

In embodiments, the washing can be accomplished, for example,successively with water and then a dilute aqueous acid, or concurrentlywith a mixture of water and a dilute aqueous acid.

In embodiments, the carbon source can have, for example, a medianparticle size of from 1 to 200 microns, such as from 2 to 175, 5 to 150,10 to 125, 20 to 100, and like particle sizes, including intermediatevalues and ranges.

In embodiments, the disclosure provides a method of making activatedcarbon, which method provides improved efficiency and cost benefits.

In embodiments, the disclosure provides a method for the economicpreparation of alkali activated carbon. In embodiments, the method usesa chemically reactive, oligomeric, solid additive in combination with analkali and a carbon source material.

In embodiments, the disclosure provides a method where the solidadditive is used as a binder for pelletizing a mixture of the carbonsource and the alkali reactant (e.g., KOH).

In embodiments, as the temperature is increased during ramp up in afirst heating step, a crosslinking reaction of the reactive oligomer(i.e., the phenolic resin) with itself and the other components of themixture takes place in from 70 to 120° C. The crosslinking of thereactive oligomer is followed by the activation reaction in a secondheating at, for example, 600 to 1000° C. The crosslinked oligomerproduct also goes through the carbonization and activation to yield ahigh performance nanostructured carbon increasing the activated carbonyield, which is in contrast to an entirely sacrificial material such asan polyethylene glycol.

Notable differences between the presently disclosed method and theaforementioned method disclosed in commonly owned and assigned U.S. Pat.No. 8,927,103 (Kirschbaum) include, for example: the binder used in thepresently disclosed methods is a reactive, solid, water-insoluble,crosslinkable, thermosetting polymer precursor, in contrast to asacrificial inert polymer as in U.S. Pat. No. 8,927,103.

In the compression or pelletization aspect of the presently disclosedmethods, the pelletization can use a carbon source having a medianparticle size of 100 microns, or more, to fashion pellets, which is asignificantly larger particle size compared to an apparent particle sizeupper limit of about 5 to 10 microns in the aforementioned U.S. Pat. No.8,927,103.

The solid oligomeric additive in the disclosed methods is subsequentlycarbonized and activated in situ to become part of the activated carbonproduct.

Other sacrificial or fugitive additives mentioned in the prior art canadversely interfere with the carbon activation so that either the KOH:carbon ratio, or the activation temperature has to be increased tocompensate for such additives.

In embodiments, the disclosed methods are advantaged for at least thefollowing reasons:

the methods can eliminate foaming by, for example, greater than 50 vol%;

the methods can permit about a significant (e.g., 2×) increase in theuseful material produced for a given activation furnace in the sameamount of time;

the methods provide an increased production rate;

the methods provide a low cost activated carbon; and

the methods provide for efficient processing of 100 microns or largercarbon source particles that enable practical industrial scalemanufacture.

In embodiments, the present disclosure provides methods that use a solidreactive pre-polymer, such as a cross-linkable Novolac phenolic resin,which when added to a mixture of a suitable carbon source and alkali(such as KOH) can: eliminate foaming without introducing by-products orcontaminants (e.g., fats); and permit the use of a large particle sizecarbon (e.g., 100 microns).

In embodiments, the disclosed methods use a crosslinkable solid additivein combination with a mixture of alkali and carbon. In embodiments, thesolid reactive thermosetting polymer precursor additive can be, forexample, a phenolic resin, such as a Novolac (e.g., available fromPlenco). This resin is different from phenolic Resols, which can be asolid or aqueous solution containing about 30% water. Although phenolicResols could also be used, the disclosed method preferably does not usea Resol resin, which has limited shelf life because the Resol resinscontinue to polymerize at even ambient temperatures (seewww.plenco.com/phenolic-novolac-resol-resins).

The Novolac resin binds well with the mixture of KOH powder and thecarbon powder, and can form chemical bonds with itself in a curing orcross-linking reaction. The Novolac resin goes through a softening stageat about 65 to 105° C., followed by the crosslinking reaction, whichcrosslinking is complete at about 120° C. After the cure (i.e., the 120°C.) the crosslinked polymer resin is strongly bonded the otheringredients. Another significant property of the Novolac resin additiveis that on sufficiently high heating during the subsequent activationprocess in an inert environment, as presently disclosed, the resinmaintains a robust fused pellet formed in the compression orpelletization step.

Although not bound by theory, the carbon particle size is not asignificant constraint for the disclosed method since, for example, a100 microns carbon particle size powder or larger can be easily andreadily processed. The additional carbon content that arises fromcarbonization of the Novolac resin additive during the disclosed methodscan also be contemporaneously activated in situ to a high performancecarbon, which result increases the activated carbon net yield, andavoids additional or unnecessary steps for removal of the Novolac resin.

In embodiments, the disclosure provides a method for producing activatedcarbon via chemical activation. The methods involve mixing a carbonizedprecursor (“carbon source”) of activated carbon with an alkali sourcesuch as KOH and a reactive solid thermosetting polymer precursoradditive. The carbonized precursor can be obtained from a natural or asynthetic source. Natural sources include lingo-cellulosic material suchas coconut shell flour, walnut shell flour, etc., andnon-lignocellulosic sources such as wheat flour, corn flour, or othercarbon sources such as green coke, needle coke, coal, charcoal, and likeknown carbon sources. Alkali sources can include, for example, KOH,NaOH, or like alkali compounds.

The thermosetting polymer precursor additive can be, for example, achemically reactive resin, preferably a solid, water insoluble, andcross-linkable phenolic resin. An example resin is a phenol formaldehydebased compound such as a phenolic Novolac resin, having representativestructures shown in FIG. 3.

Novolac resins can include a crosslinking agent such ashexamethylenetetramine, also known as hexa, hexamine, or HMTA, and likecrosslinking agents or additives, or mixtures thereof.

Novolac resins are amorphous (i.e., not crystalline), are solid at 25°C., and will soften and flow at from 150° to 220° F. (65 to 105° C.).The number average molecular weight (M_(n)) of a suitable phenol Novolacresin can be, for example, from 250 to 900, including intermediatevalues and ranges.

The disclosed methods are summarized below.

Referring again to the Figures, FIG. 1 is summary flow diagram of thedisclosed method of making.

FIG. 2 shows an exemplary pore size distribution of the activated carbonof the present methods.

FIG. 3 shows exemplary chemical structures for a phenol formaldehydebased compound such as a phenolic Novolac resin.

Solid Novolac powder resin as the thermosetting polymer precursor, and across-linking agent, can be added to the mixture alkali and carbon in aweight ratio of 0.05 to 0.3 (polymer precursor: (KOH and carbon)). Thecombined mixture can then be compressed into a pellet having a desiredsize, for example, from a 1 cm³ cubic pellet to a 15×10×5 cm briquette.The pellet or briquette can optionally be contained in a carrier boat orenclosed in sealable container. The carrier boat or sealable containercan be, for example, a metallic or other material suitable, that canwithstand the processing temperatures and conditions. The pellet can beheated in from 65 to 110° C. in air to bind the ingredients within thepellet together. Heating can alternatively be accomplished in a furnacein a suitable inert atmosphere such as nitrogen gas. The pellet, aftergreen pressing, and before or after resin cure, can optionally beenclosed in a sealable container. Following the compressing orpelletizing step the pellet can be first heat treated in an inertatmosphere at from 600 to 1000° C. to react the reactants and to formthe activated carbon. The resulting first heat treated carbon pellet wasthen washed with water and optionally with dilute acid to removeresidual potassium compounds followed by an optional second heattreatment in an inert or reducing atmosphere, such as forming gas, tocreate the desired activated carbon. The heat treatment in inert orreducing environment after activation is optional and can depend on theoxygen content specification desired in the product.

Pellet formation and subsequent containerization of pellet allows thepotassium vapor to be contained within the enclosed container andequipment corrosion issues to be minimized, so that an expensivecorrosion resistant linings (e.g., silicon carbide) in a lined furnacesare not necessary. This reduces the process cost substantially. It issignificant that the pellet maintain its integrity during the process.If the pellet disintegrates then metallic potassium emissions canincrease substantially leading to corrosion and safety issues andrequiring cost prohibitive equipment.

Since washing the activated carbon product in water and acid can be asignificant cost step in manufacture of activated carbon, it isdesirable to have a cost effective washing. The larger carbon particlesize range of the carbon produced in the disclosed process is advantagedby enabling significantly higher washing and filtration rates. It isknown that filtration rate is an inverse function of filtrationresistance, and that filtration resistance is inversely proportional tothe particle size. This happens because during filtration, particlestend to form a filter cake. A high density filter cake and smallerparticle sizes increase the resistance to filtration.

FIG. 4 shows the extent of the increase in filtration resistanceexpected with a decrease in particle size based on filtration theory(see for example, Ripperger, et al., in Ullmann's Encyclopedia ofIndustrial Chemistry, Filtration, 1. Fundamentals). FIG. 4 shows that ifthe filtration particle size in increased from 5 to 100 microns thefiltration resistance (i.e., for a solid-liquid filtration as in thepresent disclosure) declines by 3 to 4 orders of magnitude.

Filtration of a slurry containing small particles such as 5 microns isslow and costly due to an extremely slow filtration rate usingcommercially available equipment. For an industrially viable process alarger relative particle size, such as about 100 microns or more, ispreferred.

EXAMPLES

Following examples describe the invention in more detail and in greaterparticularity.

Example 1

Two grams of KOH powder was mixed with one gram of green coke powderhaving a 100 micron mean particle size, and 0.3 g of solid powderedNovolac resin including a cross-linking agent or curing agent (Plencoproduct no. 14043) in from 7.5 to 9.5 wt %, from Plastics EngineeringCompany, Sheboygan, Wis. The mixture was then pressed into 1″×0.5″pellets with a lab press to a density of, e.g., 1.0 to 1.8 g/cm³, andpreferably to 1.2 to 1.3 g/cm³. The pellets were then introduced into afurnace having a nitrogen atmosphere for a first heating including, forexample, heating with a one hr hold at each of 70° C., 80° C., 90° C.,and 110° C. After 4 hrs, the heating was continued to 800° C. with a twohr hold at 800° C. The pellets were then cooled to ambient (e.g., roomtemp.) under a nitrogen atmosphere.

Alternatively, liquid water or water vapor may be introduced into thefurnace under nitrogen atmosphere at a cool down temperature below 300°C. to ambient. The pellets, if placed in a closed container (e.g., a tincoated paint can) in the above heating process, can be removed from thecontainer. The pellets retained shape and showed excellent handlingstrength, that is, they were resistant to crumbling during typicalmanual or robotic manipulation. The integrity of the pellets issignificant since it suggested that potassium vapor was contained andthat the pelleting process addressed safety and corrosion issues. Thepellets were then washed with water followed by 37 wt % aqueous HCl, andfinally with water again to remove residual potassium compounds. Thewashed carbon powder was then ground to nominal 5 micron particle size,and then heat treated in 5 wt % H₂/N₂ forming gas at 675° C. for twohours then cooled. The resulting carbon powders were tested forperformance in an electric double layer capacitor device. The device wasmade as follows: 0.85 g of each carbon sample was separately ball milledwith 0.05 g of carbon black (Black Pearl 2000) for 10 min at 350 rpm.0.10 g of DuPont 603A PTFE was added to each separate mill jar, and thenmilled for 20 min at 300 rpm. The resulting flakes were pulse-ground ina coffee grinder until they were powderized, i.e., free flowing powders.The powdered samples were separately pressed into sheets having athickness of from 4.5 to 5.0 mil with a roll mill. The separate sheetswere placed against a piece of an aluminum current collector, and rolledthrough the mill to form an electrode sheet.

A 14 mm punch was used to punch electrodes from the electrode sheet. Thepunched electrodes were dried overnight at 120° C. in a vacuum oven.After transferring the electrodes to a glovebox, they were fashionedinto a standard aluminum/stainless steel casing for thepositive/negative electrodes in a coin cell with 90 microL of 1.2 Mtriethylmethyl ammonium tetrafluoroborate (TEMA-TFB) in acetonitrile(AN) electrolyte composition and a cellulose separator. The coin cellswere tested according to standard electrochemical procedures to measureperformance. The carbon had a measured capacitance performance of 110F/cc in the EDLC button cell.

Example 2

Example 1 was repeated with the exception that a different percentage(i.e., a doubled amount) of the same Novolac resin binder was used. Twograms of KOH powder was mixed with one gram of green coke powder havinga 100 micron mean particle size, and 0.6 g of the Plenco solid powderedphenolic Novolac resin. As in the other inventive pellet examples, thepellet maintained excellent integrity with excellent strength andhandle-ability during and after the method. The pellets were alsoprocessed into cells as Example 1. The carbon had a measured capacitanceperformance of 115 F/cc in the EDLC coin cell.

Example 3

Example 1 was repeated with the exception that the carbon sourceparticles to be heat activated in the pellet had a nominal particle sizeof about five microns. The pellets maintained excellent strength andintegrity, and the carbon had a measured capacitance performance of 108F/cc. This result, in conjunction with the results of Examples 1 and 2,demonstrates that the method can also be used with smaller carbon sourceparticle sizes.

Comparative Example 4

Example 1 was repeated with the exception that Novolac resin wasreplaced with a polyethylene glycol (Sigma-Aldrich, Cat. No. P3015,average molecular weight 200)(see the aforementioned U.S. Pat. No.8,927,103 (WO2011110543A1), to original assignee SGL, now assigned toCorning, Inc.). A pellet was made with KOH and green coke carbon asExample 1. The particle size of the selected green coke carbon was 100microns. The pellet was heated with the same schedule as Example 1.After the furnace was cooled to ambient temperature and the door wasopened, it was observed that the pellets disintegrated or crumbledindicating that the polyethylene glycol binder was unsatisfactory forachieving stable pellets, workable particle size (e.g., 100 microns),and cost reductions of the disclosed method.

The disclosed methods have demonstrated the industrial viability ofpreparing nanoporous activated carbon by chemical activation of asuitable carbon source that includes a phenolic resin additive system.The Comparative Example 4 demonstrated that the method disclosed in U.S.Pat. No. 8,927,103 was unsatisfactory for preparing activated carbonhaving a larger particle size using a pellet or briquet method since thepellet or briquet would easily crumble when handled or transported priorto the first heating. Table 1 provides a summary of the examples.

TABLE 1 Summary of Examples. Green Coke Particle Weight Ratio EDLC Size(Green Coke + capacitance Example (microns) Binder Type KOH):Binder(F/cc) 1 100 Novolac phenolic 10:1 110 resin 2 100 Novolac phenolic 10:2115 resin 3 5 Novolac phenolic 10:1 108 resin Comp. 4 100 PEG 10:1 N.M.¹¹not measured.

The disclosure has been described with reference to various specificembodiments and techniques. However, many variations and modificationsare possible while remaining within the scope of the disclosure.

What is claimed is:
 1. A method of making activated carbon comprising:compressing a mixture comprising an alkali metal hydroxide, a carbonsource, and a solid thermosetting polymer precursor into a pellet; and afirst heating of the compressed mixture at from 600 to 1,000° C., forfrom 10 mins to 24 hours.
 2. The method of claim 1 further comprisingwashing the resulting compressed and first heated mixture.
 3. The methodof claim 2 further comprising a second heating of the compressed, firstheated, and washed mixture, at from 600 to 1000° C., for from 10 mins to24 hours.
 4. The method of claim 1 further comprising placing thecompressed pellet into a closed container having a vent prior to thefirst heating.
 5. The method of claim 2 further comprising crushing thecompressed and first heated product prior to the washing.
 6. The methodof claim 1 wherein the first heating is accomplished in an containeropen to an external atmosphere.
 7. The method of claim 1 wherein thealkali metal hydroxide is powdered KOH, the carbon source is powderedgreen coke, and the thermosetting polymer precursor is a mixture of aphenolic resin and a cross-linking agent.
 8. The method of claim 7wherein the alkali metal hydroxide and the carbon source is in a weightratio of from 1:1 to 4:1.
 9. The method of claim 7 wherein the mixtureof a phenolic resin and a cross-linking agent to the mixture of the KOHand the powdered green coke is in a weight ratio of from 1:2 to 1:20.10. The method of claim 1 wherein the second heating is accomplished ina forming gas, in an inert gas, or in a combination thereof.
 11. Themethod of claim 2 wherein washing is accomplished successively withwater, and a dilute aqueous acid, or concurrently with water and adilute aqueous acid.
 12. The method of claim 1 wherein carbon source hasa median particle size of from 1 to 200 microns.
 13. The method of claim1 wherein carbon source has a median particle size of from 10 to 150microns.
 14. The method of claim 1 wherein carbon source has a medianparticle size of from 90 to 110 microns.
 15. The method of claim 1wherein compressing eliminates foaming of the mixture when heated.